• Hi Guest!
    If you enjoy and benefit from your participation at British Car Forum, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this banner)
Tips
Tips

Sprite MK III combined master cylinder issue

Share this page

JimLaney

JimLaney

Senior Member
Offline
15 years ago my MK III was undergoing rebuild. The build stopped and no fluids were ever added. I bought it recently and have started over. Yesterday I removed the pedals and the master cylinder for a re-do... cleaned up outside, removed push rods, pins, and exterior boots. The interior plunger, spring, sup will not budge. It sits soaking in DOT 4 but I'm not optimistic that they will come out. Any trick or is it a replacement issue?

If replacement, should I go with update to independent reservoirs for clutch and brakes or replace as is...?

hydraulic reservior.jpgI
 
Last edited:
Compressed air into the ports may work. Do not stand in front. If they come out the problem is that you will most likely have some pitting where the rubber was touching for all these years without moving.
You can try to hone out any pits but the best bet is to send the cylinder to Gerard to have the bores re sleeved.
 
There is a good chance that they are rusted up. Depending on where they are stuck you may be able to use pressure to free them. Either from a air compressor or a grease gun. All sort of precautions should be taken to avoid dangerous projectile pistons.

I ran a stock unit on my Sprite for several years. I just removed it last week to install a custom triple cylinder setup. Only once did I have an issue. The clutch stopped working due to a sliver of foil from a bottle seal. However, I always feared that the clutch slave would leak on a long drive and suddenly I'd be without brakes at the end of a two hour drive. Never happened ... but was always in the back of my mind.
 
I should add that if you decide you need to replace it I can sell you mine. It was from the first batch that Gerard had made. It is 3/4" both sides.
 
The Sprite IV came with separate clutch and master cylinders, so a switch is certainly feasible. If you want to go that way, I can send you pics of how it's set up on mine.
 
Jim,
There are several ways to address your MCs and I decided to go with a sleeved original from Sierra instead of the one I have pictured. The pictured MC is a pair of Tiltons and they work very well...you can even modify your pedal box for 3 MCs with a bias bar for the brakes as well as a residual valve. You can even go with a Tilton pedal box with any combination of MCs to suit your particular needs.
Rut
 

Attachments

  • IMG_1075.jpg
    IMG_1075.jpg
    78.6 KB · Views: 110
  • IMG_1076.jpg
    IMG_1076.jpg
    78.1 KB · Views: 107
There is nothing wrong with the single line system, BTW. I've had several brake failures in my life and one with a single line Spridget. All failures have given me a warning and in the case of the Spridget, the hand brake is very good. Limped home from city traffic 30 miles away. In that case PO had bent a line so that the drive shaft rubbed through it inside the tunnel.

Kurt.
 
There is a ridge in the dual master so that if you loose the clutch or brake circuit there is enough fluid in the reservoir to get you home.
 
I can see that Joe ... but what if it sloshed over? I guess I'm just paranoid.
 
Trevor, when I lost my brakes I still did have a clutch all the way home. I also had a clutch failure once with the slave piston being pushed out so no fluid down to the partition. In that case I had brakes all the way home. 50 miles in that case. Got lucky so that after a push start I could double clutch to shift and fortunately didn't have to stop at any of the stop sign's.

Kurt.
 
Correction....no double clutching without a clutch!:friendly_wink: Matched revs to shift!

Kurt
 
Similar threads
Thread starter Title Forum Replies Date
B For Sale Fully restored 1965 Austin Healey Sprite MkIII .. Spridgets Classified 0
B Fully restored 1965 Austin Healey Sprite MkIII for sale. Spridgets 0
B For Sale Fuly restored 1965 Ausin Healey Sprite MkIII Austin Healey Classifieds 0
JimLaney Sprite MK III upgrades - recommendations? Spridgets 23
PHerder ? about the rear section of the cockpit on a 1966 Sprite MkIII Spridgets 9
S Mk III Sprite cockpit surround - trying to recover Spridgets 9
S Over arched Moss Motors leaf springs for Sprite MkIII Spridgets 33
Branson '65 AH sprite MKIII gauge sizes Spridgets 2
W Parting out a 1966 MKIII Sprite Spridgets 4
abarth69 WTB Sprite MK III Steering wheel Spridgets 10
Luke_Healey Install my own convertible top on a MKIII Sprite Spridgets 3
R 1966 MK III Sprite Austin Healey 9
Tullamore Dash turn indicator. Sprite MK III Midget MK II Spridgets 1
im_a_hypnotist 66 sprite mk III dual master brake/clutch cylinder Austin Healey 2
F Holley Carburetor on Sprite? Spridgets 5
F 1966 Sprite Gearbox Spridgets 0
F Sprite Gearbox Help Austin Healey 6
vping Showing Sprite Love!! Spridgets 7
Basil Sprite Registry Form now on line Spridgets 8
sim Sprite Brake Lights Austin Healey 2
R Sprite 1275 MK 3 Austin Healey 1
drooartz Spring service of the 4-door Sprite (Morris Minor) Spridgets 8
D For Sale 1958 A-H Bugeye Sprite Austin Healey Classifieds 3
CARSINC Progress On My 1965 Sprite (update) Spridgets 3
Bayless Onslo the Sprite runs Spridgets 4
F Sprite Gearbox Spridgets 5
CARSINC Sprite bonnet emblems Spridgets 4
George Zeck SOLD!! 1964 AH Sprite MKII Spridgets Classified 0
apbos New long term project. Sprite powered rear engined race car. Spridgets 9
drooartz A disassembled sprite takes up a lot of space! Spridgets 30
CARSINC For Sale Sprite Shift Lever Spridgets Classified 0
CARSINC For Sale Sprite Front Wire Wheel Hubs Spridgets Classified 0
CARSINC For Sale Sprite Differential Spridgets Classified 0
CARSINC For Sale AH Sprite Axles and Hubs Spridgets Classified 0
Bayless What size battery for my '67 Sprite? Spridgets 5
CARSINC 1965 Sprite Bugeye Spridgets 5
CARSINC Sprite Electrical System Information Spridgets 2
Boink 3D Sprite Model Spridgets 3
A Sprite Tacho Spridgets 2
BJ8Healeys Location of VIN tag, 1964 Sprite HAN8L43421 (I know it's stamped on the frame. Looking for the tag.) Spridgets 8
S Calling All Spridget Owners & Race Fans - Sprite Turns 65 Spridgets 3
Bayless How does '67 Sprite top attach to body? Spridgets 3
SNClocks Moss Motors 5-speed install in a Bugeye Sprite Spridgets 2
adcronin For Sale MGB Turn Signal (lights, horn, indicator) Switch, New for 62-67, also Sprite MK 3 & 4, MIDGET MK 2-3 thru 67 MG Classifieds 0
D Whitworth on 59 Sprite. Spridgets 11
N For Sale Austin Healey Frogeye Sprite Spridgets Classified 0
D Sprite Model Identification Austin Healey 2
S Sprite Fuel Pump Upgrade Austin Healey 1
C For Sale Center wiring harness for a 1959 Sprite Spridgets Classified 0
Bayless My primrose Sprite Spridgets 3

Similar threads

Back
Top